Russian President Vladimir Putin said on Wednesday that Russia would send ideas to Washington within a week to follow up on his discussions with US Vice President Joe Biden about the Ukraine crisis.

After the two-hour video call, neither side mentioned a breakthrough, but they agreed to continue discussing what the Kremlin described as "this complex confrontational situation."

"We agreed we will continue this discussion and we'll do it in a substantive way. We will exchange our ideas in the very near future. Russia will draw up its ideas literally in the coming days, within a week we will give this to the U.S. side to consider," Putin told reporters.

The two leaders used Tuesday's call to layout their opposing views on Ukraine, which is bracing for an invasion by tens of thousands of Russian troops close to its border.

Biden warns Putin of 'strong' Western response to any Ukraine attack | The  Japan Times

Biden warned Putin that if Russia invaded, the West would impose "strong economic and other measures," while Putin demanded guarantees that NATO would not expand eastward.

In his first public remarks since the conversation, Putin called the question of whether Russia planned to attack Ukraine "provocative," and accused Kyiv and NATO of endangering Russia's security.

"We cannot fail to be concerned about the prospect of Ukraine's possible admission to NATO, because this will undoubtedly be followed by the deployment there of military contingents, bases, and weapons that threaten us," he said. It would be "criminal inaction" on Russia's part not to respond he added. "We are working on the assumption that our concerns, at least this time, will be heard."